It is known in the art relating to camshaft manufacturing to use cam grinding and lapping machines with traditional circular grinding and lapping wheels as shown, for example in U.S. Pat. Nos. 1,660,291 Birkigt, 1,813,503 Merryweather, 1,843,301 Player et al, 2,098,438 Stubbs, 2,195,054 Wallace et al and 2,553,831 Musyl. Such grinding machines commonly require relatively expensive grinding wheels which must be dressed often.
A camshaft grinder having multiple belts which are individually movable for simultaneously grinding the profiles of a plurality of cams of an engine camshaft or the like can make use of potentially lower cost long life abrasive belts which do not require dressing and can be easily replaced. Such a machine is shown in U.S. Pat. No. 4,175,358 wherein the grinding of individual cams is performed by straight sections of separate belts tautly drawn between idler rollers of a grinding head. Cam profiling is accomplished by a roller type cam follower mechanism while the grinding stroke is provided by infeed of a separate camshaft supporting table. This arrangement limits the ability to form cam profiles to those capable of being formed by a flat grinding surface. It also introduces inaccuracies by the use of a curved roller follower with the flat grinding surface. The camshaft table feed yields dual moving assemblies and results in the lack of a fixed center for the camshaft workpiece.
Belt grinders are also known for use with workpieces other than camshafts wherein the belts are forced into grinding engagement by curved shoes as in U.S. Pat. Nos. 2,823,494 Board, Jr. et al and 3,136,097 Laird or by wheels or drums as in U.S. Pat. Nos. 2,810,480 Carroll, 3,760,537 Bovati, 4,091,573 Schmidt, 4,292,767 Fatula, 4,382,727 Schmidt, 4,309,848 Arrigoni and 4,407,096 Steinback.